The Yale Core Center for Musculoskeletal Disorders (YCCMD) has become a prominent feature of the scientific landscape at Yale. Collaborations with investigators at other institutions, our invited speakers program (the YCCMD Seminar Series) and our website, have given us a national presence. Our Center is dedicated to fostering research in disorders of skeletal tissue and muscle, with the ultimate goal of improving human health. The Center is particularly interested in supporting the development and comprehensive investigation of animal models of musculoskeletal disorders. To encourage and sustain these efforts, the Center has established core laboratories with expertise in whole animal and skeletal-tissue analyses, molecular methods and bone-cell culture. These are the Molecular Core, the Physiology Core and the Cell Core. In the next five years we will follow the same successful blueprint that guided us through these past four years with carefully selected new initiatives planned in response to the changing needs of Centers members. Among the planned new initiatives are to offer technical and informatics support for microarray analyses in the Molecular Core and to offer stem cell isolation and culture in the Cell Core. The Physiology Core plans to offer analyses of mineralizing cultures including measurements of osteocalcin, calcium and phosphorus and techniques for staining mineral in vitro.